2,967 research outputs found

    B physics constraints on a flavor symmetric scalar model to account for the ttbar asymmetry and Wjj excess at CDF

    Full text link
    Recently Nelson et al. proposed an interesting flavor symmetric model to account for the top quark forward-backward asymmetry and the dijet anomaly at CDF simultaneously with just three parameters: a coupling constant of order one, and two scalar masses of 160 GeV and 220 GeV. However these fiducial values of the parameters lead to the branching ratio of a almost pure penguin B -> pi K decay about one hundred times larger than the experimental results. Consider also the precision electroweak constraints, the scalar masses should be at least around 500 GeV. Actually with the coupling constant larger than one, it is impossible to explain either of the two CDF measurements consistently in this model. But one may raise the charged scalar mass to, for example, 250 GeV and reduce the coupling strength to 0.6 to meet the B physics constraints. With this parameter set, the Wjj cross section is found to be in the right range. But due to the scalar mass splitting, its correction to T-parameter is about 3 sigma away from the precision electroweak constraints. In addition, the top quark forward-backward asymmetry should be well below 0.1 with this small coupling constant.Comment: 9 pages, 2 figures, accepted for publication in Phys. Lett.

    Improving Molecular Pretraining with Complementary Featurizations

    Full text link
    Molecular pretraining, which learns molecular representations over massive unlabeled data, has become a prominent paradigm to solve a variety of tasks in computational chemistry and drug discovery. Recently, prosperous progress has been made in molecular pretraining with different molecular featurizations, including 1D SMILES strings, 2D graphs, and 3D geometries. However, the role of molecular featurizations with their corresponding neural architectures in molecular pretraining remains largely unexamined. In this paper, through two case studies -- chirality classification and aromatic ring counting -- we first demonstrate that different featurization techniques convey chemical information differently. In light of this observation, we propose a simple and effective MOlecular pretraining framework with COmplementary featurizations (MOCO). MOCO comprehensively leverages multiple featurizations that complement each other and outperforms existing state-of-the-art models that solely relies on one or two featurizations on a wide range of molecular property prediction tasks.Comment: 24 pages, work in progres

    Soft corneal contact lens for postoperative comfort in patients with recurrent pterygium function

    Get PDF
    AIM:To evaluate the effect of soft contact lens on the comfort of postoperative patients with recurrent pterygium. METHODS: For 100 eyes of 98 patients after recurrent pterygium excision, the conjunctival implant with limbal stem cells from the upper part of the cornea was used, and the scleral surface of the operation area was transferred and covered. Fifty eyes were treated with corneal bandage lens for 5d(Group A)and 50 eyes were conventionally ensheathed(Group B). The time of corneal wound healing and various symptoms and signs were observed after operation. RESULTS: Compared with Group B, 1d after pterygium, the symptoms and signs of corneal irritation in Group A were significantly less(PPCONCLUSION: The corneal contact lens can obviously improve the early postoperative corneal irritation in patients with pterygium, promote corneal wound healing and relieve postoperative discomfort
    • …
    corecore